HUMAN COMFORT DESIGN

GUIDELINESPrepared by

FAIZAN

AN

D

NEHA

Buildings are designed for people, and those people are trying to accomplish a task –

whether it’s raising a family, running an office, or manufacturing a product. The building

needs to keep people comfortable, efficient, healthy, and safe as they set about their

task.

Our interface to the world is through our senses: touch, sight, hearing, smell, and

taste. Each one of these senses can lead to a greater or lesser degree of comfort

Building better is not only about avoiding problems, it should also be about creating

positively pleasurable and healthy living places.

Comfort is about the physical environment in its

totality. The issues which are most obviously

associated with comfort are:

• Temperature

• Humidity

• Noise

• Light

• Smell

• Temperature and Humidity

Temperature is the most significant component to the experience of comfort in a

space. Maintaining a person’s thermal comfort means ensuring that they don’t feel

too hot or too cold. This means keeping the temperature, humidity, airflow and

radiant sources within acceptable range. In the process our bodies’ metabolism

generates heat, which must dissipate into the surrounding air or surfaces.

Passive design strategies use ambient energy sources instead of purchased energy like electricity or natural gas.

These strategies include daylighting, natural ventilation, and solar energy.

Some ways to keep people comfortable are

• Use the sun’s heat to warm them,

• Use the wind or ceiling fans to move air when it’s too warm, and

keeping surrounding surfaces the correct temperature with good

insulation.

• HVAC equipment like boilers, fans, and heat exchangers can temper

the air temperature and humidity, but surface temperatures and

moving air have to be considered too

Active design strategies use purchased energy to keep the building comfortable. These strategies include

forced-air HVAC systems, heat pumps, radiant panels or chilled beams, and electric lights.

Adjusting For Seasons

Solar Heat Gain

Radiation

Convection

Natural Ventilation

Convection

Opening Size

Sites with high levels of acoustic noise, such as near heavy

traffic zones, may be less suitable for natural ventilation

because large openings in the building envelope can make

it difficult to block outside noise. This can sometimes be

solved by using acoustical ventilation louvers.

Also, sites with poor air quality, such as adjacent to busy

freeways, may also be less desirable for natural ventilation.

Such sites may overcome poor outdoor air quality with

filters and ducting, though this usually requires some

mechanical fan systems.

When not to use natural ventilation

Maintaining visual comfort means ensuring that people have enough light for their activities, the

light has the right quality and balance, and people have good views.

When light strikes a surface, its energy is either transmitted, abosorbed, or reflected. The color of a

surface represents the frequency of the spectrum reflected back to the observer. A surface that is

white has most of the spectrum reflected back equally, whereas one that is black has had most of

the energy absorbed.

Recommended illuminance levels

The main focus on visual comfort has traditionally been light levels, contrast, and glare. The first is the more intense the task,

the brighter the light required. This is the main reason operating rooms are much brighter than offices, which are in turn

much brighter than living rooms . The second pertains to contrast: the greater the contrast, the easier the comprehension.

This is why almost every publication uses black text on white paper. The final point is that glare is undesirable, as it makes it

difficult to see the object of attention.

Good lighting is well-distributed, is not too dim or too strong, and uses minimal energy.

Day lighting is a significant factor for pleasant interior conditions. Without sufficient day lighting, people

cannot perform well and healthy.

Daylighting, or using sunlight to illuminate your building, is an effective way to both decrease your

building’s energy use and make the interior environment more comfortable for people.

Daylighting design strategies like high or clerestory windows, light shelves, and well-placed skylights can

help distribute sunlight inside a space.

Even when you can’t use daylighting, good lighting design can reduce energy use significantly. Both are

important in Net Zero Energy Buildings.

Light fixtures ("Luminaires") are the hardware required to

hold and operate artificial light sources

The primary concern in lighting layout is to

avoid glare on activity surfaces. Such glare is a

result of light bouncing directly into user's eyes,

rather than diffusely.

The images below demonstrate just two of the many different ways of lighting a simple room to give

exactly the same lighting levels on each work surface. Each layout has advantages and disadvantages.

For instance, the first layout might use less energy, but the second layout will cause less glare and will

have fewer shadows cast on work surfaces by occupants.

Glare From Lighting Task Lighting

Separating Task and Ambient Lighting

Views are the ability for building occupants to see landscape, objects, and people outside the building. For many

occupants, the outlooks from their space or public areas are a major factor in their enjoyment of the site and it can

add considerably to the ambience of a building.

Views are measured by drawing a line of sight from a location in the building to any exterior windows; if the line of

sight to an exterior window is unbroken, that location has a view. The line of sight must be drawn at the

appropriate height for occupants; for instance, typical office workers or students are usually sitting, with eye level

assumed to be 42" (1.1m) above floor level by some building rating systems.

In order to be considered a view, the window must provide a reasonable vantage point outside the building. One

rule considers view windows ("vision glazing") to be any glazing above 30" (.75m) and below 90" (2.3m) from the

finished floor in a room. Skylights and very high windows don’t count.

Views should not be obstructed by

furniture or walls in the room.

While some people may be tall enough to

see over obstructions, an average height

should be assumed.

When designing the external works, emphasis should be put on to create and preserve natural

habitats by providing extensive lawns, keep the area is natural state, trees and hedges, green roofs,

and green facades. In some cases which the area of plot is small, rooftop planting can replace ground

sealed by construction work.

Environment plays an important role in satisfying basic human needs and quality of life. It can help to

reduce stress and also can speed up recovery. In addition, it can affect humans on a psychological

and physical level by acting as a recuperative and stimulating factor for our creative functions. In

densely developed cities, it is critical for human health to strike a balance between making space

accessible to people and preserving flora and fauna. According to some studies, dealings with nature

will affect human's mental health, whereas leisure activities in nature directly benefit to physical health

Acoustic ComfortAcoustic comfort means having the right level and quality of noise to use the space as intended.

Why it’s important

People are more productive and happy when they’re not distracted by noises from outside or from

surrounding spaces and occupants. Acoustic comfort is especially important for schools and office

buildings.

◦ Creating barriers and sound breaks between sources of noise is important. We can

optimize room shape and size to reduce echoes and reverberation. And you can

use acoustic tiles on ceilings and walls to dampen the sound.

◦ 1) Watch out for SOUND REFLECTIONS. Straight surfaces reflect sounds back into

the central space making sound clarity muddy.

◦ 2) Select ACOUSTICAL TREATMENT carefully. Different materials absorb sound

frequencies differently. Make sure your acoustical treatments are absorbing the

right sound frequencies.

◦ 3) Diminish ECHOES when necessary. Be aware that sounds traveling within 30

milliseconds of each other are perceived without echo. Sounds traveling after the

30 millisecond threshold become echoes of the original sound.

4) Don’t let other building systems get in the way. NOISE CONTROL isimportant to keep in check as other building systems (like HVAC systems)operate. Keep such clashing noises to a minimum.

5) Keep objects or other OBSTRUCTIONS out of the way. Objects thatobstruct a sound path can block high frequency sounds. (Low frequencysounds can bend around objects.)

6) Get good PATTERN CONTROL. Make sure sound systems for a room getgood sound coverage. This will prevent feed-back and other sound

distortions.

7) For out-of-the-way listening areas get DISTRIBUTED SOUND SYSTEMS. Such“delay-fill” speakers operate with an electronic delay so the soundmatches and is synchronized.

The presence of smell can deeply affect our experiences in one

location or another. The smell of flowers and grasses, dust,

exhaust ,baked goods, bleach, each suggests a particular setting

and perhaps even specific memories of places and events.

. Ventilation and infiltration are only part of the acceptable

indoor air quality and thermal comfort problem

. A large number of pollutants come a time in the air with

tobacco smoke. This affects the eyes, the nose and it is a risk

factor for different diseases. Reduce air pollution by tobacco

smoke can not be done only by increasing the air exchange

rate.

At first it may appear that the absence of all odorsmay seem ideal.

Impurities in air can be avoided by eliminating thesources of impurities, flushing out spaceswith clean air, and by filtering the air to remove

impurities.

In order to calm patients undergoing an scan with anMRI device, the rooms housing the machines are oftenlightly scented with vanilla. Thus strategic use of scentswithin a space can promote desired behaviors andemotional states, promoting a phenomenologicalsense of comfort.

Certain types of material and certain types ofconstruction are able to absorb odours and neutralisethem. In particular unfired clay products (as used inboards, blocks and plasters) and protein basedproducts such as sheepswool (as used in carpets,furnishings, and insulation) have proven absorptive

qualities.